element method

E element()

Retrieves, but does not remove, the head of this queue.

Throws InvalidArgumentException if this queue is empty.

Example:

final queue = Queue<int>();
queue.offer(42);
final head = queue.element(); // 42

Implementation

E element() {
  if (_elements.isEmpty) {
    throw InvalidArgumentException('Queue is empty');
  }
  return _elements.first;
}